Mustered in: April 23, 1861 to May 11, 1861
Mustered out: August 2, 1861
Mustered in: September 20 to October 20,1861
Mustered out: January 29, 1866

The following is taken from New York in the War of the Rebellion,
3rd ed. Frederick Phisterer. Albany: J. B. Lyon Company, 1912.
On the return of the 20th Militia from its three months' service, Col. George
W. Pratt received authority to reorganize it at Kingston as a regiment of volunteers,
and it was mustered in the service of the United States for three years between
September 20 and October 20, 1861. December 7, 1861, it received its State numerical
designation, and May 24, 1863, the three years' men of the 35th Infantry. At
the expiration of its term of service the men entitled thereto were mustered
out and the regiment retained in service. November 6, 1864, a new company joined
the regiment, taking the letter I.
The companies were recruited principally in Ulster county; quite a number
of men from the neighboring counties joined the regiment, however, and the men
enlisted for James A. Raney's Battery became part of it.
The regiment left the State October 26, 1861; served in Wadsworth's Brigade
from October, 1861; in McDowell's Division, Army of Potomac, from November,
1861; in 2d Brigade, McDowell's Division, Army of Potomac, from January, 1862;
in Patrick's, 1st, Brigade, King's, 3d, Division, 1st Corps, Army of Potomac,
from March, 1862; in 2d Brigade, same division, Department Rappahannock, from
May, 1862; in 3d Brigade, 1st Division, 3d Corps, Army of Virginia, from June,
1862; in same brigade and division, 1st Corps, Army of Potomac, from September
12, 1862; in Patrick's Provost Guard Brigade, Army of Potomac, from January
7, 1863; in 1st Brigade, 3d Division, 1st Corps, Army of Potomac, from June,
1863; in Provost Guard Brigade, Army of Potomac, from July 16, 1863; in the
Independent Brigade, 9th Corps, Army of Potomac, from March, 1865; on provost
duty at City Point, Va., from April 7, 1865; at Richmond, Va., from April 22,
1865; at Norfolk, Va., from November 27, 1865; and it was honorably discharged
and mustered out, under Col. Jacob B. Hardenbergh, January 29, 1866, at Portsmouth,
Va.
During its service the regiment lost by death, killed
in action, 5 officers, 81 enlisted men; of wounds received in action, 3 officers,
39 enlisted men; of disease and other causes, 156 enlisted men; total, 8 officers',
276 enlisted, men; aggregate, 284; of whom 22 enlisted men died in the hands
of the enemy; by the explosion of ammunition at City Point, Va., August 9, 1864,
the regiment lost, by death, 6 enlisted men.

The following is taken from The Union army: a history of military
affairs in the loyal states, 1861-65 -- records of the regiments in the
Union army -- cyclopedia of battles -- memoirs of commanders and soldiers.
Madison, WI: Federal Pub. Co., 1908. volume II.
Eightieth Infantry.—Cols., Jacob B. Hardenberg, George W. Pratt, Theodore B. Gates; Lieut.-Cols., John McEntee, Theodore B. Gates, Jacob B. Hardenberg; Majs., John R. Leslie, Jacob B. Hardenberg, Walter A. Van Rensselaer. The 80th, the "Ulster Guard," was formed by the reorganization of the 20th militia, one of the oldest militia regiments in the state, upon its return from three months' service. It was mustered into the U. S. service at Kingston, Sept. 20 to Oct. 20, 1861, for a three years' term, and was composed principally of men from. Ulster county. The regiment left for Washington Oct. 26, was assigned to Wadsworth's brigade, McDowell's division, and performed picket duty along the Potomac in the vicinity of Upton's hill, Va., during the first winter. In March, 1862, it was attached to the 1st brigade, 3d division, 1st corps, Army of the Potomac; in May to the 2nd brigade of the same division, Department of the Rappahannock, and in June, to the 3d brigade, 1st division, 3d corps, with which last assignment it fought in Gen. Pope's Virginia campaign. At the second Bull Run the 80th lost 279 in killed, wounded and missing, and Col. Pratt died a few weeks later of the wounds received in that battle. It was active at South mountain and Antietam, encamped at Sharpsburg for one week and marched through Crampton's gap, Leesburg, Warrenton and Stafford Court House to Fredericksburg, where it participated in the battle. Winter quarters were established soon after near Hall's landing and occupied until Jan. 7, 1863, when the 80th was assigned, to the provost guard brigade, with headquarters at Brooks' station and remained on duty at army headquarters until after the battle of Chancellorsville. In June, 1863, the regiment was assigned to the 1st brigade, 3d division, 1st corps, and was closely engaged at Gettysburg, where it lost 170 killed, wounded or missing out of 287 engaged. It suffered most severely in the repulse of Pickett's charge on the last day. After the battle of Gettysburg, the 80th was again ordered to headquarters for provost guard duty and con-tinued in this service until the end of the siege of Petersburg, when it shared in the final assault, April 2, 1865. From April 22 to Nov. 27, 1865, it was stationed at Richmond and then ordered to Norfolk, where it remained until mustered out on Jan. 29, 1866. The total enrollment of the regiment was 2,103, of whom 128 died of wounds and 156 from accident, imprisonment or disease. The regiment early became known for its fine fighting qualities and sustained a reputation for courage and steadiness under fire throughput its long term of service, which lasted, including its militia service, from the spring of 1861 to Jan., 1866. The regiment is classed among the "three hundred fighting regiments."

Further ReadingThis is meant to be a comprehensive list. If, however, you know of a resource that is not listed below, please send an email to ng.ny.nyarng.list.historians@mail.mil with the name of the resource and where it is located. This can include photographs, letters, articles and other non-book materials. Also, if you have any materials in your possession that you would like to donate, the museum is always looking for items specific to New York's military heritage. Thank you.

Abbey, Henry. The Ulster guard at Gettysburg on the first
three days of July, 1863, by Henry Abbey, a poem, read by the author, October
4, 1888, at the dedication of the battle-field monument of the Twentieth regiment,
New York state militia, Eightieth N.Y. volunteers. Roundout, Kingston Freeman,
1888.

Abbey, Henry. The Ulster guard at Gettysburg on the first
three days of July, 1863, verses read by the author, Henry Abbey, October 4th,
1888, at the dedication of the battlefield monument to the Twentieth regiment
of New York state militia, Eightieth New York volunteers. Second edition.
Roundout, 1891.

A brief history of the movements, operations and casualties
of the "Ulster guard," 20th regiment N.Y.S. militia, while in the
service of the United States, from April, 1861, to January, 1866, as contained
in the Fourth annual report of the Bureau of military statistics of the State
of New York. Albany: Weed, Parsons and co., 1868.

Cook, John Darwin Shepard. "Personal reminiscences of Gettysburg,"
a paper read before the Kansas commandery of the Military order of the
loyal legion of the United States, December 12, 1903.

Cook, J.D.S. BrakeColl
(Capt's personal reminiscences of Gettysburg, Dec 12, 1903)
Located at the Military History Institute in Carlisle, PA.

De Peyster, John Watts. Address delivered Wednesday, 28th
November, 1866, in Feller's hall, Madalin, Township of Red Hook, Duchess co.,
N.Y., by Brevet Maj.- Gen. J. Watts De Peyster (S.N.Y.), upon the occasion of
the inauguration of a monument erected by "this immediate neighborhood
(Tivoli-Madalin) to her defenders who lost their lives in suppressing the slaveholders'
rebellion and in sustaining the government of the people, for the people, by
the people." New York: 1867.

Finch, Edwin Ward. The frontier, army and professional
life of Edwin W. Finch, M.D. [New York: Press of Simmons, Manning and Dawson,
1909].

Gates, Theodore Burr. The "Ulster guard" [20th
N.Y. state militia] and the War of the rebellion, embracing a history of the
early organization of the Regiment, its three months' service, its reorganization
and subsequent service. New York: Benj. H. Tyrrel, 1879.

Gates, Theodore Bur. The War of the rebellion, with a
full and critical history of the first battle of Bull run, organization of the
Army of the Potomac, march to and return from Centreville, embarkation for the
Peninsula, operations of the First army, corps, campaigns and battles of the
Army of Virginia. New York: P. F. McBreen, 1884.

Gates, T.B. - BrakeColl (COL's reminiscence of Gettysburg, 1879)
Owned by the United States Army Heritage and Education Center in Carlisle, PA

Manning, Chandra. What this cruel war was over : soldiers, slavery, and the Civil War. New York : Alfred A. Knopf, 2007.
Thank you to Mark James Morreale, Chair, Department of English,
Marist College, for pointing out this resource. He writes, "Chandra Manning cites letters from Private Constant Hanks in her relatively recent monograph What this Cruel War was Over (Knopf 2007), but they do not appear to be the same letters you list for Hanks in your bibliography. A number of these Constant C. Hanks letters are dated from earlier in the war than those you list and appear to be held by the Special Collections of Duke University."

McNiff, Charles K. Letters, October 19, 1861-March 25, 1863.
Description: 5 items
Abstract: 1 letter from sister Peney [sic] Champlin to McNiff (on back of first of his letters) and 5 letters from McNiff to Peney, discuss receiving a box from home, Christmas in the army camp, friends from home and at home, and camp life generally.
Note(s): Bio/History: McNiff was a tinsmith in Tivoli, Red Hook Township, Dutchess County, New York, apprenticed to his brother-in-law C. C. Champlin, when he enlisted in Company B, 80th New York Infantry (20th Militia) on September 8, 1861. He was mustered out exactly three years later.
Located at the Abraham Lincoln Presidential Library.

North, George, Jr. Family papers, 1861-1872.
Description: .25 linear ft. (30 items)
Abstract: Correspondence from George North to his family while serving with the 20th N.Y. State Militia during the Civil War (1861-1872). Stationed in Virginia, he writes about camp, battles, and the surrounding area. North was wounded and received an honorable discharge late in 1862. Later letters were written while he was touring Europe. Other family members represented in the collection include Lucy, Mary, and Walter North, and John A. Stebbins. Collection includes a pocket sized Bible presented by the Ulster County Bible Society.
Note(s): Bio/History: Second Lieutenant, 20th Regiment New York State Militia (The Ulster Guard), Company B.
Located at the New York Historical Society, New York, NY.

Van Rensselaer, Walter A. Diary.
Submitted by Eric LeClerc, who writes: It covers the year 1863. Most of it
describes the monotony of camp life. He talks about writing letters, playing
Euchre and Whist, travelling back and forth to New York when he could get
a pass, and so on. The highlight is his description of the Battle of Gettysburg.
He describes the incident which led to the capture of a Confederate battle
flag during which he received a gunshot wound and was then knocked senseless
by an exploding round above him. The flag is the one that is now on display
in the Gettysburg Visitors Center next to the diary. The actual incident
is also mentioned on one of the two monuments to his regiment.
Located at the Gettysburg National Battlefield Park Library & Research
Center.